Final answer:
To find the value of 'a', we set up an equation using the slopes of the two lines and solve for 'a'. The value of 'a' is -7/2.
Step-by-step explanation:
To determine the value of 'a' if the straight lines 7y = ax + 4 and 2y = 3 - x are perpendicular, we need to find the slope of each line. The slope of a line is given by the coefficient of x in the equation. For the first line, 7y = ax + 4, the slope is a/7. For the second line, 2y = 3 - x, the slope is -1/2. Perpendicular lines have slopes that are negative reciprocals of each other, so we can set up the equation: a/7 * (-1/2) = -1. Solving for 'a', we get a = -7/2.